Heat pump system



May 1, 1945. G. WILKES ET AL \HEAT PUMP SYSTEM Fild Dec. 5, 1940 3 Sheets-Sheet 1 aiy 1, 1945- G. WILKES ET AL HEAT PUMP SYSTEM 3 Sheets-Sheet 2 Filed Dec. 3, 1940 May 1, 1945. G. WILKES ET AL 2,375,157,

HEAT P MP SYSTEM Filed Dec. 3, 1940 3 Sheets-Sheet 5 Patented May 1, 1945 HEAT PUMP SYSTEM Gilbert Wilkes, Jacksonwald, and Frank M. Reed, Elton Adams Township, Cambria County, Pa.

Application December 3, 1940, Serial No. 368,396

5 Claims.

This invention relates to heat pump systems, and to a unit for use therein, and, more particularly, to a heat pump system wherein a single heat pump controls the temperature at a plurality of areas where different temperatures are required.

A further and more specific object of the invention is the provision of a single heat pump unit controlling operation both of a water-heating unit, such as shown in our prior Patent No. 2,095,017, granted October 5, 1937, for Water heaters," and a refrigerating unit.

A further object, of the invention is the improvement of the water heater unit illustrated in the above-mentioned patent.

A still further object of the invention is the provision of a novel and improved means whereby the discharge from the compressor of a heat pump system may be very readily controlled to direct the same either to the evaporator of a refrigerator, or to an evaporator of higher temperature, both of which have associated therewith a common condenser.

These and other objects we attain by the construction shown in the accompanying drawings wherein, for the purpose of illustration, we have shown a preferred embodiment of our invention and wherein:

Fig. 1 is a diagrammatic showing of one form or system in accordance with our invention;

Fig. 2 is a similar view showing a slightly modi-- fied arrangementj Fig. 3 is a fragmentary vertical sectional view showing the improved water-heating unit for use in the systems illustrated in Figs. 1 and 2; and

Fig. 4 is a detail sectional view through the sump and upper end of the water inlet illustrated in Fig. 3.

Referring now more particularly to the drawings, the numeral I generally designates a water chamber for the reception of water to be heated and having associated therewith supply and discharge pipes I I and i2. Arranged within the water chamber is a condenser coil l3 receiving the discharge from a compressor it and so arranged that the discharge through the coil is in counterfiowrelation to liquid introduced to the chamber ID, as will hereinafter more particularly appear.

The discharge line I5 leading from condenser coil l3 to the usual evaporator coil l6 contains the usual liquid valve i1 and strainer l8, and has arranged therein a solenoid valve l9 and a thermal expansion valve 20. The return line from evaporator l6 communicate with the intake of compressor I l. Evaporator I6 is ventilated as by means of a circulatory fan and will, accordingly,

tend to operate at or about ambient temperatures.

The heat pump circuit thus described is substan tially that of our prior patent above identified with the addition of solenoid valve Hi the purpose of which will presently appear.

In parallel with the evaporator It which will, of course, be a relatively high temperature evaporator, we-arrange the low temperature evaporator 2! of a refrigerator 22. The supply line 23 for the evaporator 2! is connected with the line it between solenoid valve !9 and condenser l3 and is equipped at the evaporator 2! with a float valve, 2d. The return line 25 from evaporator H is connected with the return line 26 leading from the evaporator coil IE to the intake of the compressor M. The return line 25 has arranged therein a check valve 21 closing toward the evaporator 2i and both the supply and return lines 23 and 25 are equipped with shut-off valves 28. The solenoid valve i9 may either open upon the application of current, or close upon the application of current, these two forms being illustrated in Figures 1 and 2 respectively together with the necessary control circuits therefor. Since evaporator r 2| operates in a closed space and the temperature in this space is controlled as heretofore noted by a thermostat, this evaporator will operate at relatively low temperatures.

In the form shown in Fig. 1, when the lower pressure refrigerator evaporator 29 needs a cooling effect, a thermostat 29 opens a circuit 36 through switch 3i and at the same time closes a circuit 32 to by-pass electrically the water heater thermostat switch 33 so that the compressor is will be operated through its motor 3 5 regardless of the then existing temperature of water in the container l0. After the refrigerator has received all the cold it requires its thermostat opens the solenoid valve and returns the water heater to its i own thermostat control. I

. In the form shown in Fig. 2 the valve l9a closes when the refrigerator switch Ma closes its circuit 300. diverting all refrigerant to the evaporator 2! of the refrigerator. The thermostatic switch 33a of the water heater closes on contact 3% when the temperature of the water is sufficiently high and otherwise on contact 33c and, assuming that the water in the container Iilis at the predetermined high temperature, .the circuit to the motor is closed through lines 35, 36 and 8'7. At this time all of the refrigerant is circulated through the evaporator 2| and, of course, through the condenser coil it of the water heater It. If, on the other hand, the temperature is not at or above the predetermined temperature the circuit to the motor is closed through the lines 36 and 31. Obviously, with the switch 3hr open the switch 330 assumes control of the motor compressoroperation and of the heat supply to the heater 10. Obviously, in either form of the invention as illustrated in Figures 1 and 2 there will be a continual tendency of a portion of the refrigerant to be diverted to the low temperature evaporator 2| at any time that the compressor l4 may be in operation. The amount which may be so de- 10.

livered is, however, controlled by the float valve 2| of this evaporator.

The water heater I0 is more fully illustrated in Figures 3 and 4. In this water heater the principle set forth in our patent above identified are utilized, but the construction has been considerably improved. The container 50 is thoroughly insulated, as at 38, and the inlet line of the condenser coil Iii which communicates with a segregated upper section 13a of this coil is connected' with the coil by a pipe 39 leading upwardly through the container itself. The lower end of the coil I3 is provided with an enlarged sump MI in which the condensed liquid may collect, the lower end 01 this sump being reduced and comprising a conduit 4| leading downwardly through the bottom of the tank and through a surrounding inlet tube 42. Coil i3 and sump 40 have a combined capacity such that they may receive the entire refrigerant charge of the system. The inlet tube 42 is, at its lower end, sealed to the conduit 4| and the space between conduit 4| and tube 42 constitutes a water inlet through which water is introduced to the lower end of the tank and against the enlarged lower end of sump 40 so that it is thrown outwardly and i at all times subject to temperatures existing in this sump and in the conduit 4 I. This results not only in tempering of the incoming water but, likewise, in the more compiete cooling of the refrigerant employed.

We, additionally, utilize thermosyphonic action for assisting in heating the water in tank I 0. To this end we employ a coil 43 so positioned that the waste heat of motor 34 act thereon. Thiscoil has its inlet 43a connected with the lower end of the water inlet tube 42 and its outlet end 43b connected with the lower end of the tank so that during those periods when the water within the tank is at a suiiiciently low temperature there will be thermosyphonic action through coil and resultant tempering of the contents of the tank.

It will be obvious that both the systems and the particular heater structure which we have illustrated are capable of considerable modification without in any manner departing from the spirit of our invention, and for this reason we do not wish to be understood as limiting ourselves thereto except as hereinafter claimed.

We claim:

1. The combination in a heat pump system of a condenser, a pump for compressing refrigerant therein, a motor for operating said compressor, two evaporators adapted to function at different temperatures communicating with the outlet of the condenser and the intake of the compressor, a zone heated by said condenser, a zone cooled by trolled by the temperature at the low temperature 1 evaporator for diverting all of the refrigerant to the low temperature evaporator, and mean to render the motor operative upon either demand for heat in the first-named zone or refrigerant demand in the second-named of said zones.

2. The combination in a heat pump system of a condenser, a pump for compressing refrigerant therein, a motor for operating said compressor, two evaporators adapted to function at different temperatures communicating with the outlet of the condenser and the intake of the compressor, a zone heated by said condenser, a zone cooled by said low temperature evaporator, a valve controlled by the temperature at the low temperature evaporator preventing delivery of refrigerant to the high temperature evaporator, means to render the motor operative upon either demand for heat in the first-named zone or refrigerant demand in the second-named of said zones.

3. The combination in a heat pump system of a condenser, a pump for compressing refrigerant therein, a motor for operating said compressor, two evaporators adapted to function at different temperatures communicating with the outlet of the condenser and the intake of the compressor, a zone heated by said condenser, a zone cooled by said low temperature evaporator, a valve con-' trolled by the temperature at the low temperature evaporator for preventing delivery of refrigerant to the high temperature evaporator, means to render the motor operative upon either demand for heat in the first-named zone or refrigerant demand in the second-named of said zones, operatiqn of said motor upon refrigerant demand in the second-named zone occurring simultaneously with operation of said valve to prevent delivery of refrigerant to the high temperature evaporator.

4. The combination in a heat pump system of a condenser exercising a useful heating function, a compressor communicating therewith for discharging refrigerant thereto, a motor for operating the compressor, an evaporator through which the discharge from the condenser is normally circulated to the intake of the compressor, a second evaporator exercising a useful cooling function and through which second evaporator the discharge from the condenser may be circulated, means operative upon demand for heat by said condenser or refrigerant demand by said second evaporator for rendering said motor operative, and means operative upon refrigerant demand by said second evaporator for shutting off flow of the discharge from the condenser to the first evaporator, and thus forcing all of said discharge to pass through the second evaporator.

5. A device as claimed in claim 4 wherein the motor is an electrical motor and the means for causing all of the discharge of the condenser to circulate through the second evaporator is a solenoid valve included in the motor circuit and closed upon refrigerant demand by said second evaporator,.

GILBERT WILKES; FRANK M. REED. 

